1. RF & Radiator Parameters
MHz
1.8 MHz (160m)
λ = 137.57 ft
54.0 MHz (6m)
Baseline Quarter-Wave Formula
234 / f(MHz) ft
%
Compensates for tower width capacitance, apex V-droop mutual coupling, & wire velocity factor.
32' 0.8"
ft
Uncheck Auto-Resonant to enter custom wire length
Resonant (jX ≈ 0)
ft
0' 6.0" per leg
ft
2' 0.0" extra rope
2. Tower, Apex Angle & Site Limit
ft
55' 0.0"
0.40 λ above base
Radiator Attachment Angle at Tower
θ_apex = 2 × α
deg
deg
Steep V (15° / 30°)
45° / 90° Optimal Match
Flat-Top (85° / 170°)
ft
Max 60' 0.0" from tower base
Both poles within site limit
3. Poles & Ground Elevation
Pole 1 (Left Leg)
Downhill (-2.0 ft)
ft
ft
- Downhill (Lower)
0 (Level)
+ Uphill (Higher)
Pole 2 (Right Leg)
Uphill (+3.0 ft)
ft
ft
- Downhill (Lower)
0 (Level)
+ Uphill (Higher)
Radiator Wire Cut Spec
Single Leg Wire Needed (L_rad)
32.07 ft
32' 0.8"
Total Dipole (2×L)
64.14 ft
Comp. Trim Removed
-0.65 ft
Feedpoint Impedance (Z_in)
Complex Input Impedance @ Apex
51.4 - j1.2 Ω
50Ω VSWR
1.04 : 1
75Ω VSWR
1.46 : 1
Return Loss
34.2 dB
Radiation & Propagation
Peak Elevation Take-Off & Gain
42°
6.1 dBi
Wire Resonant Freq
7.150 MHz
Azimuth Circularity
±3.8 dB
Pole 1 (Left Side) Rigging Specs
Vertical Drop ΔZ₁ = 50.00 ft
Tower Base to Pole 1 (D₁)
50.00 ft
50' 0.0" horizontal
Extra Support Rope (L_rope1)
38.14 ft
38' 1.7" (+knot: 40' 1.7")
Total Slant Span (Apex to Pole 1):
70.71 ft (70' 8.5")
Ground Taped Slope Distance:
50.04 ft (50' 0.5")
Mason String Field Guide:
Tie @ 4ft on tower → hits 6.0ft on Pole 1
⚠️ Radiator + Insulator exceeds available slant span! Increase apex height, widen angle α, or bend ends.
Pole 2 (Right Side) Rigging Specs
Vertical Drop ΔZ₂ = 45.00 ft
Tower Base to Pole 2 (D₂)
45.00 ft
45' 0.0" horizontal
Extra Support Rope (L_rope2)
31.07 ft
31' 0.8" (+knot: 33' 0.8")
Total Slant Span (Apex to Pole 2):
63.64 ft (63' 7.7")
Ground Taped Slope Distance:
45.10 ft (45' 1.2")
Mason String Field Guide:
Dirt @ 45ft → hits 3.0ft on Tower
⚠️ Radiator + Insulator exceeds available slant span! Increase apex height, widen angle α, or bend ends.
Interactive Site Elevation & Rigging CAD Schematic
True-to-scale geometry showing tower, sloped terrain, radiator wires, end insulators, and support ropes
Radiator Wire (L_rad)
End Insulator (L_ins)
Support Rope (L_rope)
Level Mason String
Site Boundary (D_max)
Azimuth Radiation Pattern (dBi)
Shows V-droop end-fire vertical polarization filling broadside nulls
Total Gain
Horiz. Pol (Broadside)
Vert. Pol (Off-Ends)
Elevation Take-Off Pattern (dBi)
Ground-reflection lobes based on H_eff = 0.34 λ
Broadside Lobe
Off-End Lobe
Peak Take-Off Angle